Atroposelective Ring Opening of Cyclic Diaryliodonium Salts with Bulky Anilines Controlled by a Chiral Cobalt(III) Anion.

The present work demonstrates a CuCl and anionic chiral cobalt(III)-catalyzed enantioselective ring-opening reaction. The small-size, ligand-free copper species enabled the cross-coupling of iodonium salts with a series of bulky aromatic amines in high ee values. The chiral cobalt(III) anion causes appreciable chemical shift changes of cyclic diaryliodoniums in 1 H NMR spectra.